Chauncey m



(No Model.) Y

.. A. M. LOTHROP.

BLAGK BOARD BRASBR.

No.. 254,094. Patented Peb. 21,1882;

UNITED STATES PATENT OFFICE.

GHAUNOEY'M. LO'IHROP, OF NORWOOD., MASS., ASSIGNOR TO STILLMAN C. DAVIS, OF SAME PLAGE, AND JOHNI. FREESE, OF EAST WALPOLE, MASS.

eLAcKsoAtzD-ERASER.

SPECIFICATION forming part of Letters Patent I Application filed June 6, 1881.

To all whom it may concern Be it known that I, OHAUNGEY M. LoTlIEoP, of Norwood, in the county of Norfolk, State ot' Massachusetts, have invented a new and useful Improvement 1n 'Blackboard-Erasers, ot'

which the following is a specification.

My invention properly appertains to thecla-ss of hand-block erasers used for erasive purposes upon tablets employed in all educational insti- 1o tutions, as also for the vario us erasive'purposes to which my invention may be applicable.

It consists in an improved tablet erasingblock, as hereinafter described and claimed.

The utility of' luy-invention is fully shown in theaccompanyingdrawings,referringto which, Figure lis a view in perspective, exhibiting the application of myimproved invention. Fig. 2 indicates a transverse section in part. Fig. 3 is a longitudinal vertical through section.

A indicates the frame or body o f the eraser, preferably constructed from wood, andin form rectangular, ot'- suliicient thickness to insure strength and durability. rlhe lower or under part of the body A is scarted away one-halt its length (or, if preferable, the additional thickness may be obtained by the addition ot' material united to the part A on the dotted line b) to admit the attached and duplicated body B, which is secured to the upper body, A, at the 3o. pointC, by leather or other cheap and durable material.

At each outer end of the frames A and B are mortised openings or grooves D D, extending the width of the body. Resting upon the 3 5 under floor of said grooves are thin rigid plates,

of metal, E E, havin g their exposed edges serrated, as at E. The inner edges of these plates, to insure greater strength, are forced into suitable grooves extending into the body or frame 4ov beyond the mortised openings D D. The serrated plates E E are for the purpose of additionally securing,in connection with the grooves No. 254,094, dated February 21, 1882.

(Nomodel.)

or openings D D, the ends of the erasive fabric, of carpet, felt, or other suitable material, (indicated at F.)

For the purpose of securing the attached body B to the Lipper frame A, I introduce a screw-eye, G, in to the upper side of the body B, just back ofthe groove D, the eye of which enters into a recess, j, bored in the under side of the body A. When the erasive material is attached by its ends properly to the frame or body of the holder, as shown in Iiig, it is held in a rigid and secure position by the introduction oftheholding-barH,havingalimited movement in the end of the upper frame, A. Said bar enters through the eye of the screw G when the parts are brought together, securely locking them. The exposed end I oi' the holdingbar is formed as a ring for the purpose of suspending the eraser when not in use.

A depression, J, on one or more sides of the holding-bar H is for the reception of the stoppin K, driven from the under side of the frame, and whose oflice is to limit the movement of the holding-bar and to prevent its entire withdrawal from the frame.

Having explained the construction and oping witnesses.

OHAUNGEY M'. LO'IHROP.

Witnesses:

WM. H. MILLER, STILLMAN C. DAVIS. 

